At moments on Sunday afternoon at the Stoop, if you sat back, squinted and took the whole spectacle in, it could have been Thomond Park with the Munster of 2006 running out.

The first-half was an attritional affair but in 14 brutal second-half minutes Munster mixed power and precision to dispatch the men in quartered shirts. Quins attempted to get a foothold in the match but the Munster pack, marshalled superbly by Conor Murray at scrum-half, prevented the home side from finding their usual cohesion and rhythm.

It was a match where something had to give. Harlequins came into the quarter-final on the back of three straight losses in the Aviva Premiership while Munster were still licking their wounds after shipping 51 points to Glasgow. Questions were being asked of both sides - had Quins finally being found out or were they in a blip? Was this the end for the golden generation of Munster with both Paul O'Connell and Ronan O'Gara succumbing to the inevitability of time?

O'Connell answered any doubts surrounding his ability in front of the watching British & Irish Lions triumvirate of Warren Gatland, Andy Farrell and Graham Rowntree. He was Munster's mental and physical focal point. He was immense, putting in an all-power display reminiscent of his pre-2009 Lions form. It was hard to ignore the significance of his showing today - it proved that despite his array of injuries he still had the heart and ability to play on the biggest stage.

Munster coach Rob Penney described the second-row as a "great bloke" and also singled out O'Gara for praise. He missed two early penalties, which were sitters by his prolific standard, but as the game progressed and he had found his range, he outshone Nick Evans and kept Quins pinned back.

To a man, Munster were brilliantly effective. Alongside O'Connell and Murray's notable showings, Peter O'Mahony put in a huge performance alongside Tommy O'Donnell while James Downey proved to be a thorn in Quins' side with a couple of crowd-raising big hits.

On the platform in Richmond en route to the stadium, the Munster supporters I spoke to said that if they lost the battle in the pack, they would be defeated. They also called for more direct play rather than crabbing across the pitch. While the scrum sometimes creaked, at the breakdown the back-row was superb while Casey Laulala led their attack through the middle - it was the Munster of old.

Furthermore the Munster support also rose to the occasion. The off-field battle emulated the on-field. The Stoop had a traffic light red glow while their pitch perfect rendition of 'Fields of Athenry' dominated the 'Mighty Quin'.

Harlequins have previously talked about a constant learning process - before this season's Pool Stage, they mentioned the pain they suffered in Galway last year against Connacht and using it to their advantage this time around. Conor O'Shea would have learnt a huge amount concerning where his side are after today.

They never asserted themselves or played to the capability that the squad believes they are able of. Munster's choke tackle technique prevented Danny Care from getting the desired quick ball while their backs' only chances to attack open field came from their own 22. Chris Robshaw also had a quiet match by his high standards with the Munster back-row snuffling him up at the first available opportunity. Their lineouts also struggled with O'Connell and his lieutenant Donnacha Ryan picking off the ball with ease.

While Munster have a date with Clermont inked into their diary, Quins will now have to bounce back against Bath at the weekend if they are to continue their charge to the double instead of the potential triple which is now gone. This defeat will have hurt them - O'Shea said they will now be "written off and written down". But he wants his team to "feel sorry for ourselves for 24 hours" and then bounce back like Wales did in the Six Nations.

O'Shea's men will learn from this defeat and will look to channel the pain into future success. Munster have already experienced their fair amount of European hurt but they used this to their advantage in 2006 and 2008. Harlequins are at a different stage of their development but if they can harness their emotion and continue growing as they have done, then come a couple of years time, they may talk about this game in the same way that Munster did after their memorable European nights. But tonight, Twickenham will be painted red.